The overall objective of this research project was to determine the effect of drugs used in the Southwest Oncology Study Group on growth, growth hormone secretion and somatomedin activity. A further objective of this project was to try and relate the recurrence or suppression of the disease process with changes in growth hormone or somatomedin activity. In attempt to attain these goals we are also trying to isolate somatomedin such as to develop a rapid more sensitive assay. To evaluate the effect of the drugs used in the Southwest Oncology Study Group on these parameters we have studied the effect of these drugs in both children and in laboratory animals singly and in combinations as used iy SWOG. The effect of these drugs both in vivo and in vitro will be studied. The effect of these drugs in relationship to the patient's disease as well as his growth rate and the drugs on which the patient is being maintained will be evaluated. In the animal studies the drugs will be used in proportion to the dosage used by the Southwest Cancer Chemotherapy Study Group. We will evaluate each of the drugs for their effect on growth hormone concentration and somatomedin activity. If a positive correlation can be found between the state of the patient's disease and those parameters it may allow a suitable means of following the patient as to an impending exacerbation or the adequacy of drug therapy.